Answer:
The decision rule is
Fail to reject the null hypothesis
The conclusion is
There is no sufficient evidence to show that the proportion of all children in the United States who currently live with at least one grandparent is higher than 11%
Step-by-step explanation:
From the question we are told that
The population proportion is [tex]p = 0.11[/tex]
The sample size is n = 1640
The number found to be living with at least one grandparent is [tex]k = 225[/tex]
The level of significance is [tex]\alpha = 0.02[/tex]
The null hypothesis is [tex]H_o : p = 0.11[/tex]
The alternative hypothesis is [tex]H_a : p > 0.11[/tex]
Generally the sample proportion is mathematically represented as
[tex]\^ p = \frac{ k }{n}[/tex]
=> [tex]\^ p = \frac{ 225 }{1640 }[/tex]
=> [tex]\^ p = 0.1372[/tex]
Generally the test statistics is mathematically represented as
[tex]z= \frac{\^ p - p }{ \sqrt{\frac{p(1- p)}{n} } }[/tex]
=>[tex]z = \frac{ 0.1372 - 0.11 }{ \sqrt{\frac{0.11(1- 0.11)}{1640} } }[/tex]
=>[tex]z = 0.0077[/tex]
From the z table the area under the normal curve to the left corresponding to 0.0077 is
[tex]p-value = P(Z > 0.0077) = 0.4969[/tex]
From the value obtained we see that [tex]p-value > \alpha[/tex] hence
The decision rule is
Reject the null hypothesis
The conclusion is
There is no sufficient evidence to show that the proportion of all children in the United States who currently live with at least one grandparent is higher than 11%
